鉛化學(xué)固定的效應(yīng)分析
(1. 中南大學(xué) 資源加工與生物工程學(xué)院，長(zhǎng)沙 410083；2. 湖南農(nóng)業(yè)大學(xué) 資源環(huán)境學(xué)院，長(zhǎng)沙 410128)
摘 要: 以赤泥廢料制備含磷赤泥基顆粒作為鉛污染土壤修復(fù)材料。通過(guò)栽種韭菜進(jìn)行盆栽試驗(yàn)，于第1、5、10、20、30天取土樣。通過(guò)五步法連續(xù)提取并測(cè)定土樣中不同形態(tài)鉛的含量。觀測(cè)韭菜生長(zhǎng)情況并測(cè)定生長(zhǎng)30d韭菜中的鉛含量。以殘?jiān)鼞B(tài)鉛含量增加和其他形態(tài)鉛減少來(lái)確定修復(fù)效果，分析土壤中鉛的化學(xué)形態(tài)轉(zhuǎn)化的促進(jìn)和固定效應(yīng)以及對(duì)韭菜吸收鉛的抑制影響。結(jié)果表明：含磷赤泥顆粒可緩解赤泥強(qiáng)堿性對(duì)土壤pH值的影響，添加5%含磷3.40%的赤泥顆粒時(shí)，在修復(fù)期內(nèi)，土壤pH值與空白樣品的pH值持平。同時(shí)赤泥對(duì)磷有固持作用，有利于減少可溶磷流失。隨赤泥顆粒中磷含量增加，對(duì)鉛的修復(fù)效果顯著。施加5%含磷6.80%的赤泥顆粒時(shí)，殘?jiān)鼞B(tài)鉛增加達(dá)81.26%，有機(jī)結(jié)合態(tài)、鐵錳氧化態(tài)和碳酸鹽態(tài)鉛分別減少78.74%、85.62%和73.46%。適量施用含磷1.70%的赤泥顆粒可在保證植株正常生長(zhǎng)情況下有效抑制對(duì)土壤中鉛的吸收，鋁的吸收抑制率為68.05%。
關(guān)鍵字: 赤泥；土壤；鉛鋅；修復(fù)
（1. School of Resources Processing and Biological, Central South University, Changsha 410012, China;
2. College of Resources and Environment, Hunan Agricultural University, Changsha 410128, China）
Abstract:The red mud composite particles made up of red-mud (waste of alumina refinery) and phosphate were applied as remediation materials in Pb pollute soil. The leeks were planted for pot experiments and sampled at 1, 5, 10, 20 and 30d during the restoration. Through the five-step sequential extracting, the different phases of lead were extracted and determined. The growth of leeks was observed in 30 days and the content of lead in leeks were tested. The effect of remediation was evaluated by the increase of residue phase lead and the decrease of other phases. The promotion of chemical fixation and absorption inhibition were analyzed. The results show that the red mud-phosphate particles can relieve the increase of soil pH value caused by strong alkaline from red mud. After 5% particles containing 3.40% phosphorus are applied, the pH values of the soil samples remained unchanged to the control. And the particles have the effect of phosphate repository and the loss of water soluble phosphate is reduced. With phosphate content in particles increasing, the remediation effect of lead is significantly. When adding 5% composite particles containing 3.40phosphorus, the largest increase ratio of residual Pb is 81.26% and the decreases of carbonate phase, iron-manganese oxide phase and organic phase are 78.74%，85.62% and 73.46%, respectively. Using the composite particles containing 1.70% phosphorus, the absorption of lead is effectively inhibited as the rate is 68.05% in the base of better vegetating.
Key words: red mud; soil; lead; remediation
